General Systems Theory is a name which has come into use to describe a level of theoretical model-building which lies somewhere between the highly generalized constructions of pure mathematics and the specific theories of the specialized disciplines. Mathematics attempts to organize highly general relationships into a coherent system, a system however which does not have any necessary connections with the "real" world around us. It studies all thinkable relationships abstracted from any concrete situation or body of empirical knowledge.

The idea of a systems can be seen as a further generalized and extended thought of the following consideration. First, there is the rather sweeping claim, that "Every system has subsystems". Taking this together with "Every system has its environment", we are indeed confronted with limitless vistas of systems. One us unable to think of anything, or of any combination of things, which could not be regarded as a system. And, of course, a concept that applies to everything is logically empty. What characteristics are there which any object or group of objects could have, such that they would fail to form some kind of system? In my view, general systems theory not only does not, but further could not, answer this question. And it is partly for this reason that I believe that general systems theory is not in fact science at all, but rather naive and speculative philosophy.

General systems theory is a series of related definitions, assumptions, and postulates about all levels of systems from atomic particles through atoms, molecules, crystals, viruses, cells, organs, individuals, small groups, societies, planets, solar systems, and galaxies. General behavior systems theory is a subcategory of such theory, dealing with living systems, extending roughly from viruses through societies. A significant fact about living things is that they are open systems, with important inputs and outputs. Laws which apply to them differ from those applying to relatively closed systems.

[The objective of the Society for General Systems Research]. To encourage the development of theoretical systems which are applicable to more than one of the traditional departments of knowledge. All sciences develop theoretical systems of concepts, relationships, and models. Many of these systems are isomorphic, but their similarity is undetected because of differences in terminology and if other barriers to communications among specialists. Furthermore, systems which have been well worked out can be of assistance in the development of others. The major functions or general systems research are therefore: 1) to investigate the isomorphy of concepts, laws, and models in various fields, and to help in useful transfers from one field to another; 2) to encourage the development of adequate theoretical models in areas which lack them; 3) to eliminate the duplication of theoretical efforts in different fields; 4) to promote the unity of science through improving the communication among specialists.

Bertalanffy, Boulding, Gerard & Rappoport (1956) "Society for the Advancement of General Systems Theory: Program" in: General program. Vol.124. American Association for the Advancement of Science (1956) p. 223

A number of proposals have been advanced in recent years for the development of ‘general systems theory’ which, abstracting from properties peculiar to physical, biological, or social systems, would be applicable to all of them. We might well feel that, while the goal is laudable, systems of such diverse kinds could hardly be expected to have any nontrivial properties in common. Metaphor and analogy can be helpful, or they can be misleading. All depends on whether the similarities the metaphor captures are significant or superficial.It may not be entirely vain, however, to search for common properties among diverse kinds of complex systems... The ideas of feedback and information provide a frame of reference for viewing a wide range of situations, just as do the ideas of evolution, of relativism, of axiomatic method, and of operationalism... hierarchic systems have some common properties that are independent of their specific content...

System theory is basically concerned with problems of relationships, of structure, and of interdependence rather than with the constant attributes of objects. In general approach it resembles field theory except that its dynamics deal with temporal as well as spatial patterns. Older formulations of system constructs dealt with the closed systems of the physical sciences, in which relatively self-contained structures could be treated successfully as if they were independent of external forces. But living systems, whether biological organisms or social organizations, are acutely dependent on their external environment and so must be conceived of as open systems

There is a revolutionary scientific perspective (stemming) from the General Systems Research movement and (with a) wealth of principles, ideas and insights that have already brought higher degree of scientific order and understanding to many areas as of biology, psychology and some physical sciences... Modern systems research can provide the basic of a framework more capable of doing justice to the complexities and dynamic properties of the socio-cultural system.

Of the so-called global theories the one initially stated and defined by Bertalanffy in 1947 under the title of "general systems theory" has taken hold... Since then he has refined, modified and applied his concepts, established a society for general systems theory and published a General Systems Yearbook. Many social scientists but only a handful of psychiatrists studied, understood or applied systems theory. Suddenly, under the leadership of Dr. William Gray of Boston, a threshold was reached so that at the 122nd annual meeting of the American Psychiatric Association in 1966 two sessions were held at which this theory was discussed and regular meetings for psychiatrists were ensured for future participation in and development of this "Unified Theory of Human Behavior." If there be a third revolution (i.e. after the psychoanalytic and behavioristic), it is in the development of a general theory.

It is sheer nonsense to expect that any human being has yet been able to attain such insight into the problems of society that he can really identify the central problems and determine how they should be solved. The systems in which we live are far too complicated as yet for our intellectual powers and technology to understand.

A great many writers have manifestly believed that there is a way of considering phenomena which is sufficiently different from the well-established modes of scientific analysis to deserve the particular title of systems thinking.

General systems theory is the scientific exploration of "wholes" and "wholeness" which, not so long ago, were considered metaphysical notions transcending the boundaries of science. Hierarchic structure, stability, teleology, differentiation, approach to and maintenance of steady states, goal-directedness — these are a few of such general system properties.

There has been an increased but still rather limited response to general systems theory, as variously reflected in the work of Bateson, Vayda, Rappaport, Adams, and an interest in the use of computers, programming, matrices, etc. But the interaction between general systems theory (as represented, for example, by the theoretical work of Von Bertalanffy) has been compromised, partly by the state of field data, extraordinarily incomparable as it inevitably is, as well as historical anthropological methods of dealing with wholes. General systems theory has taken its impetus from the excitement of discovering larger and larger contexts, on the one hand, and a kind of microprobing into fine detail within a system, on the other. Both of these activities are intrinsic to anthropology to the extent that field work in living societies has been the basic disciplinary method. It is no revelation to any field-experienced anthropologist that everything is related to everything else, or that whether the entire sociocultural setting can be studied in detail or not, it has to be known in general outline.

What I consider completely sterile is the attitude, for instance, of Bertalanffy who is going around and jumping around for years saying that all the analytical science and molecular biology doesn’t really get to interesting results; let’s talk in terms of general systems theory … there cannot be anything such as general systems theory, it’s impossible. Or, if it existed, it would be meaningless.

General systems theory deals with the most fundamental concepts and aspects of systems. Many theories dealing with more specific types of systems (e.g., dynamical systems, automata, control systems, game-theoretic systems, among many others) have been under development for quite some time. General systems theory is concerned with the basic issues common to all these specialized treatments.

The Society for General Systems Theory and its publication General Systems was a mixed bag. Few authors were actually doing research -they philosophized, and many prematurely resolved dilemmas by mathematical equations in a language poorly understood by the empirical investigator.

For a long time, people have been trying to characterize or define the notion of system. After all, “systems” are supposed to be what System Theory is about. The results so far have been contradictory and unsatisfactory. This confusion at the foundations has led many to conclude that there is no such thing as a "system" and hence to deny that System Theory is about anything. Even those most sympathetic to the notion have difficulties at this level. The very founders of System Theory did not try to say what a system was; and as for System Theory, they characterized it only obliquely, by saying it comprised all studies of interest to more than one discipline. They thereby begged the entire question.

Robert Rosen, "Some comments on systems and system theory." in: International Journal of General Systems. Vol 13, (1986); p. 1

(Systems science) does not aim to ﬁnd the one true representation for a given type of systems (e.g. physical, chemical or biological systems), but to formulate general principles about how different representations of different systems can be constructed so as to be effective in problem-solving.

Systems inquiry has demonstrated its capability in dealing effectively with highly complex and large-scale problem situations. It has orchestrated the efforts of various disciplines within the framework of systems thinking. It has introduced systems approaches and methods to the analysis, design, development, evaluation, and management of systems of all kinds... Systems theory pursues the scientific exploration and understanding of systems that exist in the various realms of experience, in order to arrive at a general theory of systems: an organized expressing of sets of interrelated concepts and principles that apply to all systems.

Critical systems thinking is a robust recent trend in humanistically oriented systems work. Spearheaded by work of Ulrich (1983), Flood (1990), and Flood and Jackson (1991), this approach manages to accommodate the knowledge-constitutive interests of Jürgen Habermas (1971) and the interpretive analytical orientations of Michel Foucault (1972) through a meta-methodology involving constant critical reflection. The meta-methodology serves as the basis for the generation of a new methodology that critically applies various systems approaches to problem solving.

Systems science and technology constitute one aspect of systems thinking, but the humanities and arts make up the other. The fact that design plays such a large part in the systemic treatment of problems makes it apparent that art has a major role in it as well. Ethics and aesthetics are integral aspects of evaluating systems... the systems approach involves the pursuit of truth (science) and its effective use (technology), plenty (economics), the good (ethics and morality), and beauty and fun (aesthetics). To compare systems methodology with that of any of the so-called ‘hard’ disciplines—for example, physics—is to misunderstand the nature of systems. The worry is not that the systems approach is not scientific in the sense which physics or chemistry or biology is, but that some try to make it scientific in that sense. To the extent they succeed, they destroy it.

Complexity theory is really a movement of the sciences. Standard sciences tend to see the world as mechanistic. That sort of science puts things under a finer and finer microscope. In biology the investigations go from classifying organisms to functions of organisms, then organs themselves, then cells, and then organelles, right down to protein and enzymes, metabolic pathways, and DNA. This is finer and finer reductionist thinking.The movement that started complexity looks in the other direction. It’s asking, how do things assemble themselves? How do patterns emerge from these interacting elements? Complexity is looking at interacting elements and asking how they form patterns and how the patterns unfold. It’s important to point out that the patterns may never be finished. They’re open-ended. In standard science this hit some things that most scientists have a negative reaction to. Science doesn’t like perpetual novelty.

What is systems science? This question, which I have been asked on countless occasions, can basically be answered either in terms of activities associated with systems science or in terms of the domain of its inquiry. The most natural answers to the question are, almost inevitably, the following deﬁnitions:

Systems science is what systems scientists do when they claim they do science.

Systems science is that field of scientific inquiry whose objects of study are systems.

Without further explanation, these deﬁnitions are clearly of little use.

Within sociology there have been several system theories, differing from one another in the extent to which, for example, human agency, creativity, and entrepreneurship are assumed to play a role in system formation and reformation; conflict and struggle are taken into account; power and stratification are part and parcel of the theory; structural change and transformation – and more generally, historically developments – are taken into account and explained. What the various system theories have in common is a systematic concern with complex and varied interconnections and interdependencies of social life. Complexity has been a central concept for many working in the systems perspective. The tradition is characterized to a great extent by a burning ambition and hope to provide a unifying language and conceptual framework for all the social sciences.

Complexity by itself is not the catalyst in which a system might crash. Rather, it is how the complexity emerges in a system that determines whether that system will do what it was intended to do or morph into an unworkable organization clogged by bottlenecks and blockages. Does the system emerge through a natural course of events vetted by trial and error, or does it emerge by artificial means that detach the system from its external, self-assembled process?